The relative change of the microwave surface resistance has been measured as a function of temperature in the superconducting and normal states of UPt3 using a cavity perturbation technique. With our frequency range of ∼9-38 GHz, the microwave photon energy (ℏω) is ∼20-95% of the estimated zero-temperature (BCS) energy gap (2Δ0) of UPt3. The surface resistance shows a change in slope as the signature of TC and has a significantly weaker temperature dependence in the superconducting state than would be predicted by the Mattis-Bardeen theory. At higher frequencies, the slope tends to change by a smaller amount. No indication of collective modes at any of the frequencies was observed down to the lowest temperatures measured (∼0.1 K).
|Original language||English (US)|
|Number of pages||5|
|Journal||Physics Letters, Section A: General, Atomic and Solid State Physics|
|State||Published - 1999|
ASJC Scopus subject areas
- Physics and Astronomy(all)